export default function(content){
	const options = this.getOptions();
	const {
		preprocessor,
	} = options;
	const callback = this.async();
	if(preprocessor){
		Promise.resolve(preprocessor(content)).then((newContent) => {
			callback(null, newContent);
		}).catch(callback);
	}else{
		callback(null, content);
	}
}